chmod- allows the user to change the permission access of a file or directory.
su- allow the user to access the terminal as a super user for one command.
sudo-let the user control the terminal as a super user
chown- changes the ownership of a particular file.
passwd- allows user to change log in password.
ps- to display the active processes
kill- is used to terminate the process.
printenv- displays a list of the environment variables